Feature : - Natural crystal is the most sensitive material,- Good for high frequency, ultra high frequency extension.- Improve the sound quality- Reduce digital noise- Rosewood can enhance the texture of the instrument- Spring can enhance Powerful Bass

White Crystal cone : suitable for CD、Preamplifier & Amplifier、 bookshelf speakers,Amethyst cone : used for Power Conditioner、Power distributor and big system Speaker Citrine cone : is for any digital equipment and top vacuum tube amplifier